Login| Sign Up| Help| Contact|

Patent Searching and Data

Document Type and Number:
Japanese Patent JP6431548
Kind Code:
A production method of a rifled tube with which occurrence of seizure due to cold drawing can be suppressed is provided. The production method for producing a rifled tube (15), which includes a plurality of first helical ribs (12) on its inner surface and has an outer diameter of not more than 34 mm, includes: a step of preparing a steel tube having a tensile strength of not more than 600 MPa; and a step of producing a rifled tube by performing cold drawing on a steel tube by using a plug (2) which includes a plurality of helical grooves (21) and a plurality of second helical ribs (22) each located between adjacent helical grooves (21), the plug satisfying Formulae (1) and (2): 0.08 < W × A ˆ’ B × N / 2 À × A < 0.26 0.83 < S × A ˆ’ B × N / 2 × M < 2.0 where, W is a width (mm) of a groove bottom surface (210) of the helical groove (21) in a cross section perpendicular to a central axis of the plug; A is a maximum diameter (mm) of the plug (2); B is a minimum diameter (mm) of the plug (2) in the same cross section as that of the maximum diameter; N is a number of the second helical ribs (22) in the cross-section; S is the width (mm) of the groove bottom surface (210) in the plug longitudinal section; and M is a pitch (mm) of adjacent second helical ribs (22) in the longitudinal section.

Takashi Nakajima
Atsuro Iseta
Takeshi Miki
Shunichi Otsuka
Application Number:
Publication Date:
November 28, 2018
Filing Date:
November 24, 2015
Export Citation:
Click for automatic bibliography generation   Help
Nippon Steel & Sumitomo Metal Corporation
Mitsubishi Hitachi Power Systems Co., Ltd.
International Classes:
B21C3/16; B21C37/20; C21D9/08; C22C38/00; C22C38/18
Domestic Patent References:
Foreign References:
Attorney, Agent or Firm:
Ascend Patent Business Corporation